Excepting liver transplantation, there is as yet no widely available method for temporarily sustaining a patient who enters into hepatic failure. We have developed an extracorporeal liver assist device (ELAD) using a cloned human liver cell line and shown that it is capable of carrying our many of the major liver-specific metabolic inter-conversions. We have successfully tested this device in an animal model of fulminant hepatic failure and in sixteen human subjects to determine safety. Hepatix proposes to carry out a multisite, randomized control trial of this device to ascertain its effectiveness in treating fulminant hepatic failure. This trial will be carried out at several of the major liver centers in the United States and will be the first large scale study of fulminant hepatic failure in this country. As part of the study, we propose to collect and analyze samples from each patient in an attempt to define some prognostic features in the progression of fulminant hepatic failure. If the trial is successful, the data will be used to support an application to the US food and Drug Administration to market the ELAD in the United States. The ELAD will not only be the first non- surgical therapy for end stage liver disease, it will be the first commercially available device where live human cells are used in a therapeutic situation.